The Sacre Coeur basilica is seen in a heavy smog in Paris, France, on December 8, 2016. [Photo/IC]

From mid-January, Paris will become the first French city to launch a system that will require all cars to have a color-coded sticker indicating their age and pollution level. The stickers will allow police to control which vehicles can drive in the city center.

Cars 20 years old and older have already been banned from Paris roads since July 1, and around 120,000 stickers have been distributed. But participation in the program so far has been voluntary, and enforcement is scarce.

Beginning July 1, the city will impose bans on diesel-powered cars and vans that were first put into circulation in 2001 and trucks first registered in 2006.